/*
 *    NumericAttributeBinaryRulePredicate.java
 *    Copyright (C) 2013 University of Porto, Portugal
 *    @author E. Almeida, A. Carvalho, J. Gama
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *    
 *    
 */
package moa.classifiers.rules.core.conditionaltests;

import moa.classifiers.core.conditionaltests.InstanceConditionalBinaryTest;
import moa.classifiers.rules.core.Predicate;
import moa.core.InstancesHeader;
import weka.core.Instance;

/**
 * Numeric binary conditional test for instances to use to split nodes in
 * AMRules.
 *
 * @version $Revision: 1 $
 */
public class NumericAttributeBinaryRulePredicate extends InstanceConditionalBinaryTest implements Predicate {

    private static final long serialVersionUID = 1L;

    protected int attIndex;

    protected double attValue;

    protected int operator; // 0 =, 1<=, 2>

    public NumericAttributeBinaryRulePredicate(int attIndex, double attValue,
            int operator) {
        this.attIndex = attIndex;
        this.attValue = attValue;
        this.operator = operator;
    }

    @Override
    public int branchForInstance(Instance inst) {
        int instAttIndex = this.attIndex < inst.classIndex() ? this.attIndex
                : this.attIndex + 1;
        if (inst.isMissing(instAttIndex)) {
            return -1;
        }
        double v = inst.value(instAttIndex);
        int ret = 0;
        switch (this.operator) {
            case 0:
                ret = (v == this.attValue) ? 0 : 1;
                break;
            case 1:
                ret = (v <= this.attValue) ? 0 : 1;
                break;
            case 2:
                ret = (v > this.attValue) ? 0 : 1;
        }
        return ret;
    }

    /**
     *
     */
    @Override
    public String describeConditionForBranch(int branch, InstancesHeader context) {
        if ((branch >= 0) && (branch <= 2)) {
            String compareChar = (branch == 0) ? "=" : (branch == 1) ? "<=" : ">";
            return InstancesHeader.getAttributeNameString(context,
                    this.attIndex)
                    + ' '
                    + compareChar
                    + InstancesHeader.getNumericValueString(context,
                            this.attIndex, this.attValue);
        }
        throw new IndexOutOfBoundsException();
    }

    /**
     *
     */
    @Override
    public void getDescription(StringBuilder sb, int indent) {
        // TODO Auto-generated method stub
    }

    @Override
    public int[] getAttsTestDependsOn() {
        return new int[]{this.attIndex};
    }

    public double getSplitValue() {
        return this.attValue;
    }

    @Override
    public boolean evaluate(Instance inst) {
        return (branchForInstance(inst) == 0);
    }

    @Override
    public String toString() {
        if ((operator >= 0) && (operator <= 2)) {
            String compareChar = (operator == 0) ? "=" : (operator == 1) ? "<=" : ">";
            //int equalsBranch = this.equalsPassesTest ? 0 : 1;
            return "x" + this.attIndex
                    + ' '
                    + compareChar
                    + ' ' 
                    + this.attValue;
        }
        throw new IndexOutOfBoundsException();
    }

    public boolean isEqual(NumericAttributeBinaryRulePredicate predicate) {
        return (this.attIndex == predicate.attIndex
                && this.attValue == predicate.attValue
                && this.operator == predicate.operator);
    }

    public boolean isUsingSameAttribute(NumericAttributeBinaryRulePredicate predicate) {
        return (this.attIndex == predicate.attIndex
                && this.operator == predicate.operator);
    }

    public boolean isIncludedInRuleNode(
            NumericAttributeBinaryRulePredicate predicate) {
        boolean ret;
        if (this.operator == 1) { // <=
            ret = (predicate.attValue <= this.attValue);
        } else { // >
            ret = (predicate.attValue > this.attValue);
        }

        return ret;
    }

    public void setAttributeValue(
            NumericAttributeBinaryRulePredicate ruleSplitNodeTest) {
        this.attValue = ruleSplitNodeTest.attValue;

    }
}
